This is one of my favourite songs. Lennon wrote it while The Beatles were falling apart during the making of the "White Album". He is the only person singing/playing here. He wrote it about his mother Julia, who was run over by a drunk driver on her way to visit John when he was 17. She introduced John to music.
http://www.youtube.com/watch?v=V5A2IAgyQEg
What do you think?